From c6b61ea6536cbd8b6c72f15f21555bd2077fbd32 Mon Sep 17 00:00:00 2001 From: Matt Kiazyk Date: Mon, 4 Nov 2024 23:05:04 -0600 Subject: [PATCH] support legacy SRP (s2k_fo) logins --- Sources/AppleAPI/Client.swift | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) diff --git a/Sources/AppleAPI/Client.swift b/Sources/AppleAPI/Client.swift index 06386cb..35cb5c4 100644 --- a/Sources/AppleAPI/Client.swift +++ b/Sources/AppleAPI/Client.swift @@ -105,7 +105,7 @@ public class Client { let iterations = srpInit.iteration do { - guard let encryptedPassword = self.pbkdf2(password: password, saltData: decodedSalt, keyByteCount: 32, prf: CCPseudoRandomAlgorithm(kCCPRFHmacAlgSHA256), rounds: iterations) else { + guard let encryptedPassword = self.pbkdf2(password: password, saltData: decodedSalt, keyByteCount: 32, prf: CCPseudoRandomAlgorithm(kCCPRFHmacAlgSHA256), rounds: iterations, protocol: srpInit.protocol) else { throw Error.srpInvalidPublicKey } @@ -382,9 +382,14 @@ public class Client { return Data(hash) } - private func pbkdf2(password: String, saltData: Data, keyByteCount: Int, prf: CCPseudoRandomAlgorithm, rounds: Int) -> Data? { + private func pbkdf2(password: String, saltData: Data, keyByteCount: Int, prf: CCPseudoRandomAlgorithm, rounds: Int, protocol srpProtocol: SRPProtocol) -> Data? { guard let passwordData = password.data(using: .utf8) else { return nil } - let hashedPasswordData = sha256(data: passwordData) + let hashedPasswordDataRaw = sha256(data: passwordData) + let hashedPasswordData = switch srpProtocol { + case .s2k: hashedPasswordDataRaw + // the legacy s2k_fo protocol requires hex-encoding the digest before performing PBKDF2. + case .s2k_fo: Data(hashedPasswordDataRaw.hexEncodedString().lowercased().utf8) + } var derivedKeyData = Data(repeating: 0, count: keyByteCount) let derivedCount = derivedKeyData.count @@ -515,4 +520,10 @@ public struct ServerSRPInitResponse: Decodable { let salt: String let b: String let c: String + let `protocol`: SRPProtocol +} +extension Data { + func hexEncodedString() -> String { + return map { String(format: "%02hhx", $0) }.joined() + } }